When will a MSI package be available for download from FrontMotion's download page for the latest ESR version of FireFox (version 45)? Is there a mailing list or some other way to be notified when FrontMotion adds a new MSI package to their website?

The project may be dead, definitely not updated in a timely manner. I couldn't rely on FrontMotion Firefox anymore as Firefox 45 is needed to function properly in Windows 10, and have switched to Google Chrome with Group Policy which appears to work quite well and is officially documented by Google. I recommend deploying 64-bit Chrome whenever possible. Too bad Firefox doesn't support Group Policy natively like Chrome does.

Or you could do what every other company is doing, which is avoiding Windows 10 with a ten foot pole due to all the compatibility issues. Was Vista really so long ago that nobody remembers skipping a Windows revision due to Microsoft refusing to listen to their customers?

I see no evidence of the project being abandoned, just an overworked underpaid developer who has to spend his time on the jobs that actually pay his bills.

And Chrome? Jesus, the reason I stay with FF is to avoid Chrome's never ending stream of compatibility issues. Google makes Chrome for Google websites. Compatibility with anyone else's website is incidental.